Increased breast density is an established strong risk factor for breast cancer. However, its prognostic potential is elusive. Some studies have reported worse outcome for women with dense breasts, while most have not found an association. Mammographic tumour appearances are related to tumour characteristics. In my first project we saw that spiculated tumour appearance is associated with favourable tumour characteristics, such as positivity for hormonal receptors, lower histological grade, and lower values of proliferation marker Ki67. In the present study, we include 1 116 women from the large Malmö Diet and Cancer study, diagnosed with invasive breast cancer. Both breast density and mammographic tumour appearance were assessed on the mammogram from the time of cancer diagnosis. In addition, we have information on how the tumour was detected: via screening or clinically. This information is important to consider, since clinically detected tumours are known for carrying a worse prognosis. The women were diagnosed between 1991 and 2014 and follow up data regarding vital status and causes of death are available until the end of 2018. By conducting several survival analyses, we aim to take a wide approach on mammographic density and tumour appearance, and its relation to breast cancer prognosis.